U.S. Pat. No. 4,303,302 discloses an example of an optical beam switch in which a free fiber end of an input optical wave guide is deflected by means of a piezoelectric element, so that light is coupled in accordance with the deflection angle in different output optical guides. The free end of the input optical wave guide and the piezoelectric element together form an optical switching element. However, an air gap between the input and output optical guide leads to the following disadvantages: susceptibility of the beam switch to misalignment owing to aging and thermal effects; susceptibility of the beam switch to contamination and damage by dust and other impurities; and coupling losses owing to optical interfaces (for example, anti-reflective coatings at the air/optical guide transition).